Through the years, the increase in shipping of goods and supplies in paper cartons has necessitated the development of an opening device which will allow workers to quickly and easily open cartons to remove goods and supplies therein. The conventional carton opener, which has thus developed, is an elongated handle formed of complimentary side walls and a cutting blade, generally in the form of a razor blade, disposed between the sides. In use, one end of the cutting blade protrudes longitudinally from one end of the handle between the complimentary sides. When not in use, the fastening member which holds the sides together can be loosened and the blade retracted for storage between the sides.
During the carton opening operation, however, the occasion often arises when a worker who is in a hurry and not using a sufficient degree of care will let the razor blade or cutter slip out of the carton wall or off the end thereof, with the result that the worker may injure himself or someone else in the immediate vicinity.
Previous safety guards have been developed, as illustrated in U.S. Pat. No. 2,730,800 to Bailey; U.S. Pat. Nos. 3,052,977 to Wise; 2,376,887 to Walters; and 3,781,988 to Jones. The guards illustrated and described in each of these patents are all similar in some respects, yet all suffer the same shortcoming. That is, the blade emerges from the carton being opened previous to the emergence of the guard. Therefore, at the end of a cutting stroke, there is a moment of danger when the guard is retracted and the blade is exposed.